Di-(alkylphenyl)-alkenes



Patented Dec. 11, 1951 DI- (ALKYLPHENYL) -ALKENES I Herman Pines and Vladimir N. Ipatiefl, Chicago,

Ill., assignors to Universal Oil Products Company, Chicago, 111., a corporation of Delaware No Drawing. Application June 16, 1949,

Serial No. 99,578 v I 3 Claims. I

This invention relates to di-(alkylphenyl) alkenes and to a process for preparing the same.

This invention is based upon the discovery of a novel class of aromatic compounds containing olefinic unsaturation that may be reacted with chlorine to produce insecticides, that may be reacted with formaldehyde, and other aldehydes, to yield resins, and that may be employed as intermediates in the production of pharmaceuticals and dyes.

An object of this invention i to produce a di- (alkylphenyl) -alkene.

Another object of this invention is to produce l-p-tolyl-l-(2-methyl-5-isobuty1phenyl) -2- methyl-L propene.

One specific embodiment of this invention relates to a di(alky1phenyl)-alkene as a new composition of matter.

Another embodiment of this invention relates to a di-(alkylphenyl) -all ene having the general formula: I

. RI R Rr- I wherein R represents a straight chain alkyl group, and R1 and R2 are each separately and independ ently selected from an alkyl group and a cycloalkyl group.

A further embodiment of this invention relates to methyl-l-propene.

The methods of synthesis that may be used for preparing these di-(alkylphenyl) -alkenes comprise thesesteps including halogenation of a benzene hydrocarbon to an aryl halide in which the halogen is preferably bromine or chlorine, and reaction of this aryl halide with an alkyl aryl ketone by the Grignard method to form a di- (alkylphenyD-alkanol which is then dehydrated to yield the di-(alkylphenyl) -alkene as indicated schematically by the following equations which illustrate the synthesis of 1-p-tolyl-1-(2-methyl- 5-isobutylphenyl) -2-methyl-1-propene.

(3H3 CH;

+ Bra HBr Hr-CH-CH; Hr-CH-CH:

H: ,HI

l-p-tolyl-l- (2-methyl-5-isobutylphenyl) -2- CHI These general steps in the above indicated synthesis may" also be used in producing di-(alkylphenyl) -alkenes of the general formula ELRI (W a in which each of R1, R2, Ra, R4 and R5 separately and independently represents an alkyl group. A compound of this type may be referred to as 1- (4-alkylpheny1) -1-(2,5-dialky1phenyl)-2- alky1-1-alkene.

The nature of the present invention is illustrated further by the following example which should not be misconstrued to limit unduly its generally broad scope.

1-ptolyl- 1- (2- methyl- 5-isobutylphenyl) 2 methyl-l-propene was synthesized by the series of reactions represented by the foregoing Equa-ltions 1, 2, and 3. As the first step in this synthesis, g was prepared V. .7

isobutyltolune With'53grams (033 Mi) of bro.-

mine containing a trace of iodine (bromination catalyst) at a temperature of C. The resultant brominated product was steam -distilled,

"fractionating column having -15 plates efllwashed with dilute alkali and dried overcalcium sulfate. The bromide distilled, at 119-12130. (12 mm.); n 1.5308; (14?? 1.2057; yield-85%; MR calcd. 57.2 obs. 58.8 (new compound).

Anal. Calcd. fOl CuHisBlZ C, 53.14; H, .6.62; Br, 35.20. Found: C, 58.80; H, 6.77; Br, 34.68.

The position of the entering bromine atom was proved to be ortho to the.methy1 group by oxidation with nitric acid; 2g. was refluxed for 48 hours with 10 ml. of nitric acid (1 vol. H: 4 vol. 72% I-lNOs). One gram of 3-bromo 4- methylbenzoic acid was formed, melting at 203- 204" C., which agrees with the published melting point of this compound.

By means of the Grignard reaction, l-ptolyl 1 (2 methyl 5 isobutylphenyl) 2- methylpropanol was prepared by reacting 43 grams (0.19 M.) of 2-methyl-5-isobutylbromobenzene, 4.6 g. (0.19 M.) of magnesium, 31.0 g. (0.20 M.) of p-isobutyryltoluene in 120 ml. of ether to form a Grignard complex which was decomposed by pouring it over a solution of 14.5 g. (0.25 M.) of ammonium chloride dissolved in ml. of water. The reaction product was distilled at 5mm. pressure on a column of about 10-15 theoretical plates and separated into p-isobutyltoluene (10.3 g.); p-methyl-isobutyrophenon (16.0 g.) and a principal fraction distilling at 153-160/4 mm. (25.5 g.). This principal fraction-corresponded to a mixture of the desired tertiary carbinol and the corresponding olefin. The carbon-hydrogen analysis showed that partial dehydration of the carbinol occurred during distillation.

Anal. Calcd. for C22HsoO:C, 85.16; H, 9.68. Calcd. for 0221128: C, 90.35; H, 9.65. Found: C, 88.47; H, 10.02.

The resultant mixture of the mentioned tertiary carbinol and corresponding olefin was disv ciency.

The olefin, namely, l-p-tolyl-1-(2- methyl 5 isobutylphenyl) 2 methyl 1- propene which was obtained in an yield boiled at a temperature of C. at 3 mm. pressure, had a refractive index 12.3 1.5550, and

-a densitydi of 0.9402, and a molecular refraction MR1) calculated value of 96.1, observed value 99.7.

Anal. Calcd. for CzzHzs: C, 90.34; H, 9.66. Found: C. 89.90; H. 9.87.

" We claim as our invention:

1. A di-(alkylphenyD-alkene having the general formula phenyl)-2-methyl-1-=propene.

Name Date Dixon et a1 Sept. 28, 1948 Number 

1. A DI-(ALKYLPHENYL) -ALKENE HAVING THE GENERAL FORMULA 